The use of PowerShell functions in mathematical expressions

  I have had a try these days powershell, The use of a function inside made me very angry .

Customize a function first function g($x) = { $x*$x }

And then by command g(5)+g(5), Actually output 25, instead of 50!

But found , If you use it like this

$a = g(5)

$b = g(5)

$a+$b

Can output 50

 

Finally, I found out , That's what it says

(g(5))+(g(5)), perhaps (g 5) + (g 5)

To output 50

 

I really don't know what to say .